This study is intended to define internal heat recirculation mechanism and to research the characteristics of burned gas within porous block for flammibility limit expansion. In this study, four experimental model were selected for its experiment. So, in each case gas temperature and porous block wall temperature were measured within combustive reacting porous block and Unburned hydrocarbon concentration and nitri oxide concentration were measured. From its experimental results, it is known that the hightest temperature of gas exceeded the adiabatic flame temperature and the flame was stabilized even at equivalence ratio 0.43 and excellent exhaust characteristics.
